That is nice - do share the code - we are working on something where we want to stack up a bunch of content areas one on top the other on both left and right side - with the ability to control the content in them. The content in any of the rendition blocks being any combination of words, graphics and widgets. Your code will help to serve the basis of this.
got something like this already sorted.
will release as open source soon.
need to write documentation and a few minor bugfixes.
I have just started using silverstripe and am aiming to produce the exact layout you got to work which looks great - can I please take you up on your offer of sharing the code? I am new to CSS and this would really help - thanks!
I have only included the minimal in-line comments in the code, but if you want to know specifics post the questions and I will try to answer them here.
I should mention that I have used this layout on my live site now: http://www.tellura.co.uk/ and it is working out well.
Good luck and if you improve it (shouldn't be difficult) share it back!